1. Field of the Invention
This invention relates to a method for providing digital data. More particularly, the present invention relates to a data storage apparatus, a data providing system and a data providing method for freely providing desired digital data to the user, while eliminating illegal copying of digital data such as video contents.
2. Description of the Related Art
It is currently possible to easily provide high quality digital contents to the user due to the recent development of rental systems of information storage mediums storing digital data such as CDs (compact discs) and DVDs (digital versatile discs). For example, the user may visit a rental audio/video shop, choose an information storage medium, or a disc, storing the contents he or she wants and take it home from the shop after paying an appropriate amount of money as rental fee that is determined as a function of the lease of the disc. To return the disc to the shop, he or she may visit the shop once again and hand it over to a shop assistant or put it into the collection box of the shop.
However, with such a system, the user has to visit the shop personally. Some users may feel it a trouble to visit the shop personally while others may miss the time limit for returning the disc and become forced to pay the arrearage charge. Thus, many existing disc rental systems are inconvenient and unattractive to the users. Additionally, the music data recorded on a CD can easily be copied by means of a PC (personal computer) at present so that some users may illegally copy the contents of CDs to violate the copyright law and infringe the copyright of the author.
Rental systems for disseminating the contents of books and CDs (normally audio and/or visual works) as electronized perceptual information (perceptual information providing systems) have been proposed to solve the above-identified problems (see, inter alia, Japanese Patent Application Laid-Open Publication No. 2001-195407).
The rental system disclosed in the above patent document comprises a dedicated data station and dedicated portable terminal apparatus and perceptual data of audio and/or visual works stored in the data station are downloaded and output sequentially from a display and/or an earphone to get to a user. The perceptual data downloaded from the data station are controlled for the time limit of availability thereof by the timer mounted in the portable terminal apparatus so that they are automatically erased when the time limit of availability of the perceptual data comes. Thus, such a system is free from the inconveniences of many existing rental systems that require the user to return the rented discs.